Arc stud welding gun



June 6, 1950 c, CRAVEN 2,510,620

ARC STUD WELDING GUN Filed Sept. 10, 1949 [rm/enter: Kenneth C. CTaveTh by W His Attorney.

Patented June 6, 1950 ARC STUD WELDING GUN Kenneth C.

New York Craven, Fitchburg, Mass., assignor to General Electric Company,

a corporation of Application September 10, 1949, Serial No. 114,989

4 Claims.

My invention relates to the welding of a metal stud to a metal body or workpiece, and has for its object the provision of a simple, reliable and compact stud welding gun.

More specifically, my invention relates to a stud welding gun that can be attached to an element of a machine to form the welding head thereof, or can be used by hand in which case a suitable handle is attached.

Another object of my invention is to provide a stud welding gun in which the welding circuit is effectively insulated from the circuit of the operating solenoid and in which the solenoid operating element is sufiiciently removed from the arc to protect it from damage due to heat.

One arrangement in use for welding studs to metal bodies employs a ceramic ring or ferrule around the weld end of the stud to facilitate the welding operation. The studs being welded may be in the shape of a pin to be bent over after insulation is applied or may be threaded as when they are to be used to hold a wooden flooring in place on a steel structure. They may also be formed of less expensive metal and welded to serve as tongs to position blanks of valuable alloys during forging operations to save an extra heating and drawing operation. The studs themselves may be of either circular or non-circular cross-section. In all of these cases the same ceramic ring or ferrule may be used for studs having an equal maximum cross-sectional dimension since the clearance between the ring and the stud is not critical.

Another object of my invention, is to provide a retaining device within the gun itself to hold the ceramic ring during the welding operation.

For a more complete understanding of my invention, reference is made to the accompanying drawing, the single figure of which is a sectional view of one embodiment of my invention adjacent a workpiece to which a stud is to be welded.

Referring to the drawing, I have shown a stud-welding gun I adjacent a metal workpiece 2. The frame of the gun I comprises a cylindrical body section 3, a domed cover 4 and a domed nose secured to the body section 3. The nose 5 threadedly supports a replaceable tubular section 6, the length of which depends upon the length of the stud to be welded. The nose may be suitably formed of either a metal or a nonconducting material such as plastic. When metal is used, the nose is insulated from the body section 3 and from the welding conduit extending through the nose.

A stud holder 1 extending into the nose comprises an electrically conducting head 8, to which is attached a cable 9 at a terminal post l0, and

an adapter II. The cable 9 extends through an aperture l2 in nose 5. A stud I3 is shown in position in a cavity [4 of head 8. Cavity I4 is provided peripherally with a plurality of balls l5 biased towards the center of the cavity by springs 16 to grip the end of the stud l3. The adapter I l is secured to head 8 by bolts I1 and is electrically insulated from the head. A rod l8 has its lower end attached to adapter II and its upper end to a plunger IQ of a solenoid 20 mounted upon a plurality of pillars 2| and secured thereto by bolts 22. Wires of the solenoid circuit lead to an outside circuit (not shown) through holes 23. A spring 24 bearing upon a flange 25 of rod 18 biases the rod away from the solenoid.

A ceramic ring or ferrule 26 having an inside 20 diameter greater than the diameter of stud I3 is inserted in the tubular section 6 and held in position by a plurality of balls 21 positioned around the circumference of the tubular section and biased toward the center thereof by springs 28.

As ring 26 is held by the gun itself the necessity of holding the inside diameter of the ring to a close tolerance and of assembling the ring to stud I3 is eliminated. Further, while the ceramic ring is eventually destroyed in use, the fact that there is clearance between the ring and the stud and that the ring is carried by the gun permits the gun to be slipped off the stud so that the ring can be reused in successive weldings, effecting a further saving in ceramic rings.

In addition to forming a support for the ceramic ring, the nose and tubular sections particularly in the configuration illustrated in the drawing, provide protection against injury for the stud holder 1 and the rod l8. Likewise, location of the solenoid coil in the end of the gun opposite the stud holder protects the coil from the heating efiect of the arc.

In operation, a ceramic ring '26 is positioned within barrel 6 and a stud I3 is pushed into the stud holder 1. The gun is pressed against the work 2 over the spot to which the stud is to be welded, thereby causing the stud holder to be pushed upward against the spring 22. A hand switch (not shown) on the gun or readily accessible to the welder then may be used to connect a supply of current to conductor 9 in the main welding circuit and to connect a current supply to the coil of solenoid 20. These circuits may be energized simultaneously or with an instud in the direction of the stud axis. If the ceramic ring has not ben daniagedin" the process;

it may be used during subsequent welding opera-- tions.

said nose and a tubular section replaceably o s 29. 31!, a d 3| a tapped inthesidaot welding gun can be attached to a machine or supplied with able. 'Alternately, aswitchactuated by thetravelof rod rlaas. the. gun is passed towards the. work-' piece may be employed to operate the control mechanism inst'eadof the hand. operated switch. described;

While certain specificembodiments have been shownan described; it' will, of course, be under.-' sto'od th'at various modifications -maybe made without departing: from :the invention. The appended claims... are, thereforaintended to cover any such modifications within the true spirit and scope of theinvention.

What: I claim .astnew and-desire- Letters Patent of I the United States is:

L'AstudWelding gunfor-effecting the welding o r-metallic parts sue'h as studs to metallic bodies comprising a cylindrical body section, a'doinedcover enamed nose sectionremovably attached-to saidbody section, a tubular section communicating into saidn'ose' section, a solenoid providedwith a plunger mountedupon said body section, a rod provided witli'a flange slidably mounted lnsaidboelysection and pivotally attached to said plunger, spring means biasing said plunger "away nemesis soienoidf an adapter mounted upon said rod and an electrically con ducti-ve' stud holder mounted upon and electricall "insulated from said adapter,*saidstud holder lid-ting a cylindrical caVitftherein, a plurality of spring biased baILretainer-S mounted around ti-ie p'eriphe'ryfof said cylindrical cavity to grasp wistud-"ther'ebetween," and *aplu'rality of spring biased'ballretainers mounteda'round the periph-' ery of said tubular section" to grasp a ceramic ring therebetween. 7

2ii'In"anarc stud welding gun including a frame; stud holding means for frietionall-y engaging the end-of astud and imparting lengthwise movement thereto relative'to said frame, a member'mounted'on' said frame and enclosing said holdingmeans', said' me'mber having an a suitable handle to make it portto secure by opening centered in the line of movement of a stud and said stud extending through said opening, and means aligned with said opening mounted upon said member for frictionally retaining a, non-metallic ring member about the arcing end portion of said stud coaxially with said line of movement.

"*3; Inez arc stud elding gun including a center section, a nose mounted upon said center section, a stud holder linearly movable Within mounted upon said nose communicating into said iaving its axis coincidental with the line'ofTmovement 'o'f-said stud holder to enclose astud held byfs a'i d stud holder, and friction means mounted within the outer wall of said tubularsertionteretai a non-metallic ring centric with said tubular section.

4 Astud welding gun for effecting the welding of metallic parts such as-studs to metallic bodies comprising a'iicylindrical body, a domedcovier and :"a' domednosei removablyvattached. to and. forming c'ompartmentsi at opposite ends of. said. body section, an electrically. "conductive. stud. holderv'andanu adapter mounted. together and line arly movable within said noses. compartment, said holder being. electrically insulated "from. said adapter, said.-stud..holder' having a. cavityfthere= in, a plurality of s'pringfbiasedball retainers mounted around the .periphery efssaid cavity to g'rip 'oneend-.of. a :stud. therein, bindingmpost. means mountedlzupon xsaid stud-holder, a cable secured to said. binding post I means extending. through said. nose 1 and f insulated therefrom, a solenoid. provided. with a plunger mounted :upon saidbody section withinvsa-id cover. compartment, a f. rodLprQVided with :a fiangeislidably mounted in. saidbody'section and. connected between said. plunger and said'fladapt'er .to'.transmit linear mo.-v tion ttherebet-ween spring meansmounted. in said bodyv section and. engaging. said.;flange to. bias saideholderlaway. from isaidv solenoid, a tubular section-mounted upon said: nosemmmunicating thereinandmounted Withitsflaxis coincident with." the line ofesaid; li-nean motion, and. friction. re.-. taming..means.mounted =within the,.outer walls. of.saili tubular sectiontoremqvablyxetainanone metallic ring concentric therewith.

. 1 C. CRAVEN July. .1... .1933,

e- .1 Feb 2 .9% Apr.- 20. .9528. 

